The effect of alkaline activated reservoir sediments used as a binder in concrete on its compressive strength

Sediment as the product of erosion processes is found in every water body and reduces the storage capacity and the lifetime of water reservoirs. The quantity of sediment which affects downstream areas and also their quality complicate sediment management. Dredged sediments are on the borderline of soils, water and waste. The favourite dredged material management options are natural options and beneficial re-use is a way to encourage the use of dredged material as a potential resource and not as a waste. Sediments are regarded as a suitable raw material in construction industry. This paper is focused on the study of the effect of sodium hydroxide as a pozzolanic activator of sediments from Ruzin reservoir (Slovakia) used as a binder in concrete on the compressive strength of hardened concrete. Reservoir sediments are mechano-chemically and chemically activated with the addition of solid sodium hydroxide into milling process. Hardened mixtures containing 40% of binder replacement by activated sediments were tested for compressive strengths after 28, 90 and 365 days of curing. The results show that sodium hydroxide is not an effective pozzolanic activator for sediments.